Ok, maybe not completely. I still think that marines can be beneficial allies to the Eldar, although I'm not as convinced as I use to be. I have switched my allied detachment from 20 bikers and a captain (+stormtalon and thunderfire cannon) to 10 bikers and a chapter master (+ other stuff). The bikes are still hard hitting and give me a tough unit but this frees up about 220 points for other goodies such as hornets (if FW allowed) or a second wraithknight (on the building table currently). I played this list last week vs. Jeff and it worked out nicely. As I don't see combat squading these guys much, I'll probably consider dropping them down from a 10 man unit in the future as well, but I do like the large squad. It also worked out nicely that he made a number of mistakes but that is separate. The choice to ally largely will depend on if the cannon and talon prove themselves. So far they are doing good but not great.
Next up for my testing is to drop a unit of guardians for a pair of ranger units instead. And to test them vs. a larger variety of armies (so far only eldar, dark eldar and deamons)